On the threshold of powered flight

Dennis Parks is Curator Emeritus of Seattle’s Museum of Flight.

During the closing years of the 19th century, there were important events that brought the development of aircraft to the edge of powered flight. It was a period of great expectations, full of such developments as the gasoline engine, the automobile, electric lights and the telephone. The experiments of this time in aeronautics by the likes of Lilienthal, Chanute, Maxim, and Langley were important in providing inspiration and laying the technical foundations that the Wright brothers and others would follow.

OTTO LILIENTHAL

Born in Germany, Otto Lilienthal’s exploits in manned glider flight made the first significant contribution toward the achievement of powered flight. Fascinated with bird flight from his youth, he received an excellent education at the Berlin Technical Academy. After service in the Franco-Prussian War, he began serious research in aeronautics with a series of experiments designed to establish the scientific principles of bird flight.

This research, including important studies of the lift created by a curved surface, was published in 1889 as Der Vogelflug Als Grundlage Der Fliegekunst (Birdflight as a Basis of Aviation). This seminal book influenced many aeronautical researchers. In 1891, after more than 30 years of study, Lilienthal began work on a series of gliders to demonstrate the practical applicability of his research. His bat-shaped gliders consisted of broad wings made of delicate curved wood spars covered with silk, with a harness in the center from which Lilienthal would suspend himself.

He built an artificial hill near Berlin that he used for a running takeoff into the wind. Control was obtained by weight shifting. Over the next five years he built 18 gliders and made more than 2,000 flights. The results of his glider experiments were published in Zeitschrift Fur Luftschiffahrt in November 1893 as “The Carrying Capacity of Arched Surfaces in Sailing Flight.” This work was translated and published by Octave Chanute in his book, Progress In Flying Machines, in 1894. Lilienthal was on the verge of trying powered flight with the use of a small carbide gas engine when he died from injuries from a glider crash.

OCTAVE CHANUTE

Born in Paris, France, Chanute came to America when he was 6. He was one of the country’s leading civil engineers when he became interested in aeronautics. His interest led him to do a great deal of research and correspondence on the subject, which was reported in his 1894 book, Progress In Flying Machines.

In 1896, when he retired from his occupation as a civil engineer, Chanute began his own experiments in manned flight. With the help of another engineer, August Herring, he developed several gliders. These ranged from designs with as many as six tiers of wings down to the more effective biplane model, in which his assistants made more than 300 flights down the sand dunes of Indiana near Chicago. His knowledge of bridge building techniques brought to aeronautical construction structural strength that was unknown before. He also became a close consultant to the Wright brothers in their developments.

SIR HIRAM MAXIM

Maxim, an American by birth, and better known for the machine gun of his name, provided an interesting sidebar to the history of aircraft at the end of the 19th century in England.

Maxim set out to prove his theories of wing-lift and propeller thrust through the construction of a huge machine. It was not intended to fly but to lift itself off the ground. He started out with the testing of airfoils on a whirling arm and also experimented with propellers. The huge test rig he built was basically a biplane with a lifting area of 4,000 square feet and two monoplane elevators, one fore, one aft.

It was powered by two lightweight steam engines of his design that produced 180 hp each. Each engine drove a propeller of over 17 feet in diameter. The four wheel undercarriage ran along 1,800 feet of steel rails, which had a wooden guard rail to restrain the vehicle from raising any higher than 2 feet. The total weight of the machine and crew of three was 3-1/2 tons. On the test flight the machine rose in the air and caught on the rails and brought the test to a stop. That performance proved beyond Maxim’s expectations the thrust of his propeller design. Having proved his point on thrust and lift, he stopped his experiments.

SAMUEL PIERPOINT LANGLEY

Langley was apprenticed in architecture and civil engineering but turned his interest to astronomy and astrophysics. From 1887 until his death, he served as the secretary of the Smithsonian Institution. He started his serious investigations of flight in 1887 with the construction of a whirling arm test mechanism to test bird wings and airfoils. He also tested 30 to 40 rubber-powered model airplanes. In 1891 he started building his steam-powered models called “Aerodromes.”

His first successful one, the No. 5 Aerodrome, was built as a tandem wing machine. It first flew on May 6, 1896 — a distance of more than 3,000 feet. The machine had a wing area of about 65 square feet and the steam engine of about 1 hp drove two midship-mounted propellers.

Based on his success, Langley received a federal grant to develop a full-size man-carrying aircraft. This was completed in 1903. Attempts to fly the machine in October and December 1903 ended in failure with the craft crashing into the Potomac River. Nine days after the last attempt, the Wright brothers successfully demonstrated their flyer.

THE WRIGHT BROTHERS

In 1896 the Wright brothers read regularly of the gliding experiments of Lilienthal. His death while gliding increased their interest in flight and gendered a desire to solve the problem of powered flight. They also studied the efforts of Maxim, Chanute and Langley. From these studies they came to realize the obstacles on the path to success.

Dennis can be reached at [email protected].